Lightning arrester



March 23, 1937. B, E, O'HAGAN 2,074,755

LIGHTNING ARRESTER Filed March 2, 1935 lNvEN-roR ernard'. OHgan.

E" @um HLS ATTORNEY UNITED STATES PATENT OFFICE LIGHTNING ARRESTERBernard E. OHagan,

The Union Switch Swissvale, Pa., assigner to & Signal Company,Swissvale, Pa., a. corporation of Pennsylvania Application March 2,1935, Serial No. 9,074

9 Claims.

My invention relates to lightning arresters. More specifically, myinvention relates to improvements in a lightning arrester of the typedescribed in Patent No. 1,022,717, issued April 9 1912 to Alexander JayWurts.

One object of my invention is to provide an arrester of the typedescribed above which will insure greater protection against thepossibility of short circuiting. Another object is to provide anarrester which may be manufactured more economically. A still furtherobject of my invention is to provide an arrester which may be readilyand economically serviced and maintained in the field.

I will describe a few forms of lightning arresters embodying myinvention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Figs. 1 and 2 are plan and side elevationviews, respectively, showing one form of lightning arrester unitembodying my invention. Fig. 2a is a view illustrating a part of thearrester shown in Figs. 1 and 2 and also embodying my invention. Figs.3, 4, and 5 are views illustrating modified portions of the arresterunit shown in Figs. 1 and 2 and each also embodying my invention. Fig. 6is an enlarged fragmentary isometric view illustrating a portion of thearrester shown in Fig. 5 and also embodying my invention.

Similar reference characters designate similar parts throughout theseveral views.

Referring first to Figs. l, 2, and 2a, the reference character Adesignates one of a plurality of uniform electrodes, preferably brass,which is of relatively large cross-sectional area and which has anenlarged head 2 at one end and a point at the other end. Theseelectrodes are arranged in pairs with a spark gap between their pointsand may be supported in parallel metal plates B in any suitable manner,as, for example, by punching aligned holes in the plates, and insertingthe electrodes in the holes. As here shown, the plates B are spaced apredetermined distance and are held in parallel :alignment by theshoulders 3 of an insulating member C (see Fig. 2a) which is inserted inaligned slots provided in the plates B. The enlarged heads 2 of theelectrodes A may be held in electrical contact with the plates B, andthe plates B may be held against the shoulders 3 of the insulatingmember C in any suitable manner, such, for example, as by spring clipsE. The spring clips E, when compressed, hold the parts of the assembledunit securely in proper engagement and alignment with each other. The

clips E may be held under compression, as here shown, by cotter keys Finserted in holes 4 provided in the outer ends of insulating member C.As here shown, the points of each pair of electrodes are enclosed in atube G of insulating material, preferably a glass tube, having a hole,the diameter of which is such as to provide a loose fit over theelectrodes A. By such a tube I provide a means for insulating each pairof electrodes from the adjacent pairs, thus permitting the pairs ofelectrodes to be placed much closer together than would be permissiblewithout such insulation. Another feature of the tube is the protectionof the spark gap from dust, dirt and insects, etc., which might permitthe electrodes to become electrically connected. A further feature ofthis tube is the indication of the condition of the electrodes; that is,when the electrodes have become fused the fact is indicated by thediscoloration of the tube. Still another feature of the tube is therelatively large inner surface of the tube adjacent the spark gap whichis free from Contact with the electrodes, so that increased protectionagainst short circuits is provided in the event of coating of the innersurface of the tube by vaporization of the points of the electrodes as aresult of lightning discharges.

Since the tubes are provided for protection only and are not requiredfor maintaining the alignment or spacing of the spark gap, such tubesneed not necessarily have a uniform length and diameter. The cost,therefore, of the tubes Will be considerably less than would obtain ifthe tubes were required to be of uniform dimensions.

If the electrodes should become fused or the electrodes or tubesotherwise damaged by lightning discharges, it is apparent that byWithdrawing the cotter keys F, such damaged parts may be very readilyreplaced in the field Without removing the arrester from service exceptduring the time repairs are being made. Ordinarily the electrodes andtubes will be the only parts which will require replacement, therefore,the lightning arrester embodying my invention will be economical tomaintaim The reference character H designates one form of terminal blockupon which the lightning arrester unitembodying my invention may bemounted.'

The manner in which the lightning arrester embodying my inventionfunctions to protect apparatus from lightning discharges is well knownand, therefore, no explanation of the principles involved in itsfunctioning is being made herein.

Referring next to Fig. 3, the reference charactor AI designates amodified form of electrode which may be applied to the lightningarrester illustrated in Figs. 1 and 2. The electrode AI has a portionnear its pointed end of relatively small cross-sectional area and aportion near its head of relatively large cross-sectional area. It isapparent that an electrode of this form provides for a greater surfaceinside the tube G adjacent the spark gap which is free from possiblecontact with the electrode, so that short-circuiting of a, pair ofelectrodes is less liable to occur as a result of coating of the insidesurface of the tube by vaporized metal.

Referring now to Fig. 4, the reference character A2 designates anotherform of electrode which may be applied to the lightning arrester unitshown in Figs. 1 and 2. The electrode A2, as here shown, is ofrelatively small diameter and may be an ordinary brass toilet pin withthe clip E2.

end opposite the point bent at right angles to the axis of the pin. Inorder to hold the electrode A2 in proper alignment, a metal sleeve J isprovided which has substantially Athe same outside diameter as thealigned holes in the plates B, and which extends through the holes intothe tube G, so that the collar of the sleeve is in engagement with theouter face of the plate B. The electrode A2 is inserted in a holeprovided in the sleeve' J of substantially the same diameter as theelectrode. in contact with the sleeve J and the sleeve is held incontact withfthe plate B by the spring An electrode of the form shown inFig. 4 provides for a relatively large increase in the distance from theelectrodes to the inside surface of the tubepadjacent the spark gap,and, therefore, further removes the possibility of short-circuiting dueto vaporization of the electrode. Moreover, since the electrodes A2 maybe common toilet pins, the cost of such electrodes may be materiallyless than the electrodes A or Ai.

Referring now to Figs. 5 and 6, the reference character Ci designates aninsulating member similar in all respects to the previously describedinsulating member C, except in its method of application to thelightning arrester unit. As here shown, the member Ci is a cylindricallyshaped key. The key Ci is provided at each end with shoulders 5 and withrectangular shaped heads 6, the heads 6 being spaced from the shoulders5 by a portion of reduced diameter 1. When the rectangular shaped heads6 are inserted into similarly shaped aligned slots 8 and 9 in the platesBI and spring clips El, respectively, the shoulders 5 will maintain. thepredetermined spacing between the plates BI, and the heads 6, whenturned at right angles to the slots 8 and 9 after the clips arecompressed, will hold the parts of the assembled lightning arrester unitsecurely in their proper positions. The member Cl, together with plansBI and spring clips El may be applied as just described to the assembledlightning arrester unit shown in Figs. 1 and 2.

From the foregoing description of lightning arresters embodying myinvention, it is apparent that I have provided new and improved forms oflightning arresters which minimize the danger of short-circuiting due topossible vaporization of the electrodes, which may be manufacturedeconomically and which may be readily and economically repaired in thefield.

The electrode is held -Although I have herein shown and described only afew forms of lightning arrester units embodying my invention, I do notWish to limit myself to these specific forms, as various modificationsmay be made therein without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

1. A lightning arrester comprising two/parallel plates provided with aplurality of aligned holes and with aligned slots, an insulating memberextending through said slots and provided with shoulders which cooperatewith the confronting faces of said plates to maintain a predeterminedspacing between said plates, a plurality of electrodes one disposed ineach of said holes and each provided at its outer end with a head andterminating at its inner end in a point, the parts being so proportionedthat when the heads of two aligned electrodes are engaging the outerfaces of the associated plates the points of the electrodes will have apredetermined spacing between them, a plurality of tubes of insulatingmaterial one disposed on each aligned pair of electrodes between saidplates and enclosing the points of said electrodes, and two clips onesecured to each end of said insulating member and each cooperating withthe associated electrodes to hold their heads in engagement with theassociated plate.

2.A A lightning arrester comprising two parallel plates each having aplurality of relatively large aligned holes, a plurality of uniformelectrodes one disposed in each of said holes and each havingv arelatively small cross-sectional area, a metal sleeve disposed in eachaligned hole and each having an outside diameter substantially the samesize as the aligned holes and an inside diameter substantially the samesize as the cross-sectional area of the electrodes, means for spacingsaid two parallel plates a predetermined distance and means formaintaining said electrodes and the associated sleeves in contact witheach other and in contact with the associated plates.

3. A lightning arrester comprising two parallel plates provided with aplurality of aligned holes and with aligned slots, a plurality ofelectrodes one disposed in each of said holes and each provided at itsouter end with a head, two spring clips one engaging the heads of theelectrodes in each plate and each having a slot which aligns with theslot in the associated plate, and an insulating key extending throughall of said slots and provided with shoulders which cooperate with saidplates to maintain a predetermined spacing between them, and with a headat each end which cooperates with the associated clip to hold the clipin engagement with the heads of the electrodes, the heads of said keybeing so shaped that they will pass freely through said slots when saidkey is rotated to one position relative to the slots but not when thekey is rotated to another position relative to the slots.

4. A lightning arrester comprising two parallel plates having apredetermined spacing therebetween and each provided with a hole whichis in alignment with the hole in the other plate, a pair of electrodeseach having a head, one electrode being disposed in the hole in eachplate to provide a spark gap between the confronting ends of saidelectrodes, and removable spring means for holding the head of eachelectrode in engagement with the associated plate.

5./ A lightning arrester comprising two parallel plates having apredetermined spacing therebetween and each provided with a hole whichis in alignment with the hole in the other plate, a pair oi' electrodeseach having a head, one electrode being disposed in the hole in eachplate to pro- 5 vide a spark gap between the confronting ends of saidelectrodes, an insulating tube enclosing said confronting ends forprotecting said spark gap, and removable spring means for holding thehead of each electrode in engagement with the l associated plate.

6. A lightning arrester comprising two parallel plates having apredetermined spacing therebetween and each provided with a hole whichis in alignment with the hole in the other plate, a pair l of electrodeseach having a head, one electrode being disposed in the hole in eachplate to provide a spark gap between the confronting ends of saidelectrodes, an insulating tube enclosing said confronting ends, theparts being so proportioned 20 that a relatively large portion of theinner surface of said tube is free from contact with said electrodes,and removable spring means for holding the head of each electrode inengagement with the associated plate.

25 7. A lightning arrester comprising two parallel plates having apredetermined spacing therebetween and each provided with a hole whichis in alignment with the hole in the other plate, a pair of electrodeseach having a head and each having 30 the portion nearest the head ofrelatively large cross-sectional area and the portion farthest from thehead of relatively small cross-sectional area, one electrode beingdisposed in the hole in each plate to provide a spark gap between the 35confronting ends of said electrodes, and removable spring means forholding the head of each electrode in engagement with the associatedplate.

8. A lightning arrester comprising two parallel plates having apredetermined spacing therebetween and each provided with a relativelylarge hole which is in alignment with the hole in the other plate, apair of electrodes each having a head and each having a relatively smallcrosssectional area, one electrode being disposed in the hole in eachplate to provide a spark gap between the confronting ends of saidelectrodes, a metal sleeve disposed in each aligned hole and each havingan outside diameter substantially the same as the aligned holes and aninside diameter substantially the same size as the cross-sectional areaof the electrodes, and removable spring means for maintaining the headof each electrode and the associated sleeve in engagement with eachother and in contact with the associated plate.

9. A lightning arrester comprising two parallel plates each providedwith a hole which is in alignment with the hole in the other plate, aninsulating member extending through said plates and provided withshoulders which cooperate with the confronting faces of said plates tomaintain a predetermined spacing therebetween, a pair of electrodes eachhaving a head, one electrode be'- ing disposed in the hole in each plateto provide a spark gap between the confronting ends of said electrodes,removable spring means for holding the head of each electrode in contactwith the outer face of the associated plate, and means cooperating withthe outer ends of said insulating

